₹2,500 की धनराशि साधारण ब्याज पर 3 वर्षों में ₹3,250 हो जाती है। उसी धनराशि पर उसी वार्षिक ब्याज दर से 2 वर्ष बाद वार्षिक रूप से संयोजित चक्रवृद्धि ब्याज कितना होगा?

A sum becomes 25 times of itself when invested for 48 years at r% simple interest per annum. Find the compound interest earned if Rs. 51,200 is invested at r% per annum when interest is compounded half-yearly, for 1.5 years.

Simple interest on a certain sum at 4% per annum for 2 years is ₹80. What is the compound interest on the same sum for the same period at the same rate?